ants in one’s pants

(idiom) to be restless

Example Sentences:

My 8 year-old son has ants in his pants because he is going to watch a football match tomorrow. He’s so excited.

Roberta had ants in her pants because she had a presentation to give in her business class.

From the Blogs:

Ants in Your Pants and Jumping Jacks

Media:

Similar idioms:

1. keep one’s pants on
2. caught with your pants down
3. give someone the benefit of the doubt